• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.435-442
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• 2002

Fluid Confirmation Tests(FCT) on 1500 ground Anchors install in weathered rock were carried out to investigate upper and lower limit of elastic elongation, frictional resistant of fixed anchor body, mobilized angle between anchor body and soil. All the measured data were analysed and compared with theoretical equations. The frictional angles of diaphragm wall and anchorage system in weathered rock showed nonlinear curve between upper and lower limit of standard elongation. The FCT results indicated that the frictional resistant angles increased with higher values of surcharge load. The quality assurance on the fixed anchor location was investigated by means of measuring elastic elongation during the FCT, and comparing these with theoretical design length, the quality of anchors in this particular site found to be above average standard. The results of this research works with provide valuable guide line on quality assurance of anchors system as well as resonable prediction of friction resistance between the fixed anchor body and the weathered rock.

• Structural Engineering and Mechanics
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• v.71 no.4
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• pp.417-432
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• 2019

Seismic performance analysis of steel-brace reinforced concrete (RC) frame using topology optimization in highly seismic region was discussed in this research. Topology optimization based on truss-like material model was used, which was to minimum volume in full-stress method. Optimized bracing systems of low-rise, mid-rise and high-rise RC frames were established, and optimized bracing systems of substructure were also gained under different constraint conditions. Thereafter, different structure models based on optimized bracing systems were proposed and applied. Last, structural strength, structural stiffness, structural ductility, collapse resistant capacity, collapse probability and demolition probability were studied. Moreover, the brace buckling was discussed. The results show that bracing system of RC frame could be derived using topology optimization, and bracing system based on truss-like model could help to resolve numerical instabilities. Bracing system of topology optimization was more effective to enhance structural stiffness and strength, especially in mid-rise and high-rise frames. Moreover, bracing system of topology optimization contributes to increase collapse resistant capacity, as well as reduces collapse probability and accumulated demolition probability. However, brace buckling might weaken beneficial effects.

• Steel and Composite Structures
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• v.17 no.1
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• pp.105-121
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• 2014

A fundamental limitation of steel structures is the decrease in their load-bearing capacity at high temperatures in fire situations such that structural members may require some additional treatment for fire resistance. In this regard, this paper evaluates the structural stability of fire-resistant steel, introduced in the late 1999s, through tensile coupon tests and proposes some experimental equations for the yield stress, the elastic modulus, and specific heat. The surface temperature, deflection, and maximum stress of fire-resistant steel H-section columns were calculated using their own mechanical and thermal properties. According to a comparison of mechanical properties between fire-resistant steel and Eurocode 3, the former outperformed the latter, and based on a comparison of structural performance between fire-resistant steel and ordinary structural steel of equivalent mechanical properties at room temperature, the former had greater structural stability than the latter through $900^{\circ}C$.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.103-112
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• 1998

The earthquake resistant design for roadway bridges introduced in 1992 is conducted according to the "Standard Specification for Roadway Bridges", Division V, Seismic Design and the first revision of the Standard was done in 1996. However, dur to different concepts of the earthquake resistant design from those of the other designs, the provisions given in the Standard are still not applied appropriately. In this paper the verification of the earthquake resistant capacity of a bridge with typical configurations, 5-span steel box girder bridge, is carried out based on the application rules of the present Standard in order to provide clear understandings about the earthquake resistant verification and the earthquake resistant design as well.n as well.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.144-150
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• 2000

This study dealt with the comparison of lateral baring capacity for vertical PHC pile between predicted and measured values driven in weathered granite soils to build world cup gymnasium in Kwangju area. Recently, the calculation of horizontal bearing capacity of piles foundation has been considered very important for earthquake or wind resistant design in Korea. During this study , Matlock & Reese, Broms and Chang's methods were selected in prediction of lateral resistant of PHC piles. As for case study, the prediction values were compared with 5 measured ones based on ASTM. The result showed that prediction values proposed by Matlock & Reese , Chang and Broms were smaller that real values. Three proposed methods by Matlock & Reese and Chang based on lateral deflection and Broms by ultimated lateral resistance turned out valid in view of engineering practice.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.466-470
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• 2000

Recently, the calculation of horizontal bearing capacity of piles foundation has been considered very important for earthquake or wind resistant design in Korea. This study deals with the lateral resistance of PHC pile instead of vertical capacity for earthquake resistant design as well as wind. As case study, the prediction values were compared with measured ones based on ASTM. During this research, Matlock & Reese, Davisson & Gill, Broms and Chang's methods were selected in calculating prediction of lateral resistance of PHC piles. In decomposed granite and clayey soils, The result showed that prediction values proposed by Matlock & Reese(Davisson & Gill), Chang and Broms were smaller values than real values. four proposed methods by Matlock & Reese(Davisson & Gill) and Chang based on lateral deflection and Broms by ultimate lateral resistance turned out valid in view of engineering practice.

• Structural Engineering and Mechanics
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• v.39 no.2
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• pp.287-301
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• 2011

This paper is focused on the residual capacity of steel columns, as a damage criterion. Load-Impulse (P-I) diagrams are frequently used for analysis, design, or assessment of blast resistant structures. The residual load carrying capacity of a simply supported steel column was derived as a damage criterion based on a SDOF computational approach. Dimensionless P-I diagrams were generated numerically with this quantitative damage criterion. These numerical P-I diagrams were used to show that traditional constant ductility ratios adopted as damage criteria are not appropriate for either the design or damage assessment of blast resistant steel columns, and that the current approach could be a much more appropriate alternative.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.100-106
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• 2006

Today, restricted energy sources, environmental considerations and the high cost of transporting fuel have limited the number and location of available power plant sites. The pressures resulting from these conditions have tended to require the construction of long, high-capacity, high-voltage power lines. it's used to adapt to STACIR/AW(Super Thermal-resistant Aluminum alloy Conductors, aluminum-clad Invar-Reinforced) conductor for coping with these situations. STACIR/AW conductor was formed by the combination of INVAR/AW as the core for low sag and super thermal-resistant aluminum alloy conductor for current capacity increase. increase of temperature by current capacity and long span lines make the susceptible to the deterioration of thermo-mechanical properties(conductivity, tensile strength, E-modulus and twist property et al). In the present work, changes of thermo-mechanical properties with aging have been studied in STACIR/AW $410 mm^2$ conductor with forms of single wire and strand wire.

• Fire Science and Engineering
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• v.31 no.6
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• pp.60-66
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• 2017

Steel framed building can be destroyed due to deteriation of structural stabilities in a fire. This leads a TMC Fire Resistant Steels and this study analyzed the structural stabilities such as a deflection and a reduction of maximum load capacity for the structural beams built with a TMC Fire Resistant Steel. In this study the structural stabilities were evaluated using a mechanical properties in high temperatures not only a heat transfer theory but a heat stress anlaysis with a statistically determinated beam and a statistially indeternated one. The results showed that a TMC Fire Resistant Steels demonstrated a little lower those of Fire Resistant Steels.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.181-190
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• 2007

A fire-resistant steel with enhanced load-bearing capacity has been developed to enable structural elements such as columns and beams withstand exposure to severe fire conditions. To precisely evaluate the fire-resistant performance of structural elements that compose fire-resistant steels, mechanical properties such as yield strength and elastic modulus are essential. To obtain the mechanical database of fire-resistant steels at high temperatures, tensile tests at high temperatures were conducted on steels of two kinds of thicknesses. The results showed that the thickness difference could not affect the mechanical properties at a high temperature.